Electric and hybrid electric vehicles often use sources of high voltage such as battery packs or fuel cells that deliver direct current (DC) to drive vehicle motors, electric traction systems, and other vehicle systems. These systems typically include power inverters to convert DC input from the power source to a 3-phase alternating current (AC) output compatible with electric motors and other electrical components. Such inverters generally include both power and capacitor modules interconnected by a busbar system that distributes current throughout the inverter. Such busbar systems often involve two or more intricately designed laminar positive and negative electrodes that overlap for most of the area of the busbar.
Moreover, some conventional inverters have been observed to incur voltage spikes when currents flowing through the power module abruptly change, such as when the inverter is switched on or off. The magnitudes of these voltage spikes are related, at least in part, to the inductance of the busbar. More particularly, the relationship between inductance (L), current (i), voltage (V), and time (t) is described in equation (1):V=L*(di/dt)  (1)This equation demonstrates that voltage spikes are intensified for systems that have a high inherent inductance. That is, even relatively small changes in current can produce relatively large voltage spikes if the inductance is high. A busbar may contribute substantially to the total inductance of an inverter system because of the relatively long current pathway between its various input and output terminals.
Many busbar design factors such as the amount of overlap between positive and negative electrodes can affect the inductance of a busbar system. Because current flows in opposing directions in each electrode, this overlap effectively reduces the overall system inductance. While laminar designs offer an overlapped current pathway for the majority of area, the interconnecting elements that transfer current from a primary busbar to a subsystem receiving the current, such as a power module, have non-overlapping connector assemblies. Accordingly, the contribution of such assemblies to overall system inductance can be significant.
Accordingly, it is desirable to provide a low inductance connector assembly for a busbar system to reduce voltage spikes when power modules are switched on or off. Further, it is also desirable if such a connector assembly has a reduced material cost and part count, and is simpler to assemble. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.